1. Field of the Invention
The present invention concerns fiber communication systems.
To be more precise, the present invention relates to the field of multichannel optical connection means designed to connect a plurality of optical fibers simultaneously to a planar optical component or to connect a plurality of optical fibers of one cable to a plurality of optical fibers of another cable.
2. Description of the Prior Art
Until now optical fibers have mainly been used in long distance transmission systems, trunk networks and interexchange networks.
From now on, however, optical fibers will be increasingly used in distribution networks with fiber terminations in distribution chambers in buildings and eventually in the home.
As the number of customers concerned increases, the overall economics of the network become of vital importance.
Two contrasting scenarios using two types of architecture are emerging for the design of these networks.
In accordance with the first scenario a single down channel serves multiple users by means of multiplexers, couplers, and splitters.
The cost of the sender component and the fiber is therefore shared between the users so served.
In accordance with the second scenario, there is one fiber per user but the send and receive components are treated collectively. This simplifies network management and there is a saving in terms of the integration factor of the component strips used.
These contrasting options necessarily entail:
coupling of send and receive components to couplers and to splitters and then to the fibers themselves, and PA1 coupling of the send component strips to guides and then to the fibers. PA1 to reduce connection costs compared to the prior art, PA1 to allow disconnection of the optical fibers, PA1 to enable gluing on site, PA1 to achieve low levels of reflection, and PA1 to achieve better stability than existing products. PA1 making a multichannel optical connection wafer having a plurality of optical outlets disposed on a common face in a predetermined configuration and with a precise pitch, PA1 disposing said connection wafer on a support having mechanical positioning means, PA1 placing the assembly comprising said connection wafer and said support facing a complementary reference termination comprising a reference face having mechanical positioning means adapted to cooperate with those of said support to define a unique relative position between them and a multichannel optical connection reference plate fixed rigidly to said base and having on a common face at least two optical outlets disposed in the same predetermined configuration as said connecting wafer, PA1 dynamically aligning two outlets of said connection wafer with respective outlets of said connection plate by three independent relative movements between said connection wafer and the associated support, and PA1 fixing said connection wafer to said support when said alignment is obtained.
Although these functions are at present implemented by assembling discrete components, the cost of the latter, the lengths of intermediate fiber used, the connectors required and the associated space requirements soon make these uncompetitive in comparison with the planar optics technique and its associated functions usually called OEIC.
The well-known principle of planar optics consists in forming optical waveguides of appropriate geometry on plane substrates which can be made from glass, silicon, silica, lithium niobate or even polymer materials, for example.
As indicated in the article "Status of glass and silicon-based technologies for passive components, Martin Mac Court IOOC 93", there are currently three techniques for aligning an optical fiber with the axis of an optical waveguide or of a second fiber and maintaining their relative positioning after alignment.
The first technique is a dynamic alignment technique of optimizing the power transmitted from the fiber to the guide or from fiber to fiber, and then gluing the fiber and the guide (or the other fiber) together.
The second technique is a static alignment technique of etching very high precision V-grooves on a substrate.
The third technique is a semi-static alignment technique of bonding fibers into highly accurate V-grooves and micropositioning of the resulting structures in line with a substrate.
These solutions are not entirely satisfactory, however.
The first solution is time-consuming and the time taken is proportional to the number of outlet fibers to be aligned.
The formation of high-precision V-grooves in a substrate, as required for the second and third solutions, is a costly high-technology operation.
The techniques used until now, as outlined above, have the further major disadvantages of not allowing disconnection of the fibers, of poor stability, and of not easily achieving low levels of reflection at the component.
An object of the present invention is to improve multichannel optical connection devices for optical fibers.
To be more precise, subsidiary objects of the invention are: